To measure the shape of the fast corneal surface of the human eye, we propose the design and characterization of a compact corneal topographer using the capabilities of a smartphone. The performance evaluation of the compact corneal topographer includes the calculation and compensation of the distortion introduced by the smartphone lens used to acquire the images and the evaluation of a reference surface. To demonstrate the feasibility of our proposal, we performed surface topography measurements on some human corneas and compared the results with those obtained by a commercial corneal topographer. We showed that the results obtained with our algorithms were consistent with other methods that analyze the corneal surface.
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http://dx.doi.org/10.1364/AO.449875 | DOI Listing |
Jpn J Ophthalmol
January 2025
Department of Ophthalmology, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
Purpose: Chemical chelation with ethylenediaminetetraacetic acid (EDTA) is an established treatment for calcific band keratopathy (CBK), whereas removal of calcium deposits from the subepithelial layer of the cornea may cause corneal irregularity. Using Fourier harmonic analysis, we analyzed the corneal topography in eyes with CBK treated by EDTA chelation.
Study Design: Retrospective, single-center study.
Eye Contact Lens
January 2025
Lewis Katz School of Medicine at Temple University (F.A.), Philadelphia, PA; and Wilmer Eye Institute (L.D.M., K.B., A.C.), Baltimore, MD.
Objective: To determine if scleral fittings that occur before corneal cross-linking (CXL) are still successful after the procedure.
Methods: This prospective study included seven patients with keratoconus or post-laser-assisted in situ keratomileusis (LASIK) corneal ectasia who were fitted with scleral lenses then underwent CXL. Four patients (six eyes) had keratoconus and three patients (five eyes) had post-LASIK ectasia.
Cureus
December 2024
Department of Ophthalmology, The University of Jordan, Amman, JOR.
We present the case of a 23-year-old male who experienced vision loss in his left eye 15 months after undergoing bilateral transepithelial photorefractive keratectomy (T-PRK). Despite the absence of any significant preoperative topographical risk factors in either eye, corneal ectasia was later confirmed in the left eye, while the right eye remained normal. Subtle asymmetry in topometric indices and a borderline high Index of vertical asymmetry (IVA) reading suggested the possibility of early subclinical keratoconus, potentially increasing the risk of post-refractive ectasia.
View Article and Find Full Text PDFBiomed Phys Eng Express
January 2025
National School of Electronics and Telecommunication of Sfax, Sfax rte mahdia, sfax, sfax, 3012, TUNISIA.
Deep learning has emerged as a powerful tool in medical imaging, particularly for corneal topographic map classification. However, the scarcity of labeled data poses a significant challenge to achieving robust performance. This study investigates the impact of various data augmentation strategies on enhancing the performance of a customized convolutional neural network model for corneal topographic map classification.
View Article and Find Full Text PDFJpn J Ophthalmol
January 2025
Department of Ophthalmology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Purpose: To determine whether corneal biomechanical parameters can predict ectasia progression.
Study Design: Retrospective observational study.
Methods: The baseline corneal biomechanical parameters of 64 eyes of 41 young patients (age, < 25 years at the first visit) who were diagnosed with keratoconus (KC) or suspected KC at Osaka University Hospital and followed up for more than two years were reviewed.
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